Good question. Here is a little background, forgive me if it is too remedial but it is meant for anyone who might need the info:

They are potentiometers and they work just like the knobs on any electronic device.

I am not sure of the value of the samples from this company and I don't have mine with me.

Assuming that we got some made with the right physical size and appropriate value, we could use them to control the parameters (note, timbre, tone and/or volume. etc) of an electronic circuit.

I am toying with the idea of building or buying a synth circuit and mounting the whole thing into the body of an old cello I have taking up space in the garage.

Wasn't there a schematic for the theremin cello posted somewhere around here?

What if we mounted two or three ribbon controllers side-by-side and had the ability to tune them independently of each other to do chords? That way the player could just barre the three ribbons on the neck and play chords.

Maybe the right hand controls could have some way to adjust the volume of each in some ergonomic, intuitive way.